1. Technical Field
The present invention relates in general to a method and system in a data processing system for the establishment of relationships between reference objects in an object oriented environment and a data object outside an object oriented environment and in particular to a method and system in a data processing system for the association of reference objects within an object oriented environment with a data object outside an object oriented environment. Still more particularly, the present invention relates to a method and system in a data processing system for the modification of an associated data object in response to a modification of any reference object, and a modification of all reference objects in response to a modification of an associated data object.
2. Description of the Related Art
Object oriented programming has experienced growing popularity with application developers primarily due to the ability of this type of programming to reuse code. The object oriented environment more closely models "real world" entities.
An object in an object oriented environment consists of related pieces of code and data. An object generally has a library of methods which are essentially unique to an object, giving an object its specific behaviors. The "class" of an object defines a grouping based on one or more properties, and an "instance" is a single item in a class. For example, a class of an object could be considered as analogous to professions, i.e. lawyers, doctors, engineers, and programmers, with an instance of an object being analogous to a particular individual in a class. Agents are objects within an object oriented computing environment that do work for a user.
A class defines methods for constructing new instances and also instance methods which define how an instance behaves and reacts to incoming messages. The instance variables define the particular features of an instance of an object such as an individual's salary. These instance variables may be defined or may be empty, awaiting definition. An instance's data structure is described by its collection of instance variables. Pointers are used to point to a structure in object form.
In some computer systems, objects within an object oriented environment may be linked to objects outside the object oriented environment so that communication between the two types of objects may occur. In these prior art systems, an object is created in the object oriented environment which includes information necessary to translate data from an object oriented format into a format suitable for the other environment. In this manner, objects within the object oriented environment may communicate with external objects.
It should therefore be apparent that a need exists for a method and system for establishing reference objects within an object oriented environment which are associated with a data object outside the object oriented environment, whereby modifications are made to an associated data object in response to modifications made to any reference object, and whereby modifications are made to all reference objects in response to modifications made to an associated data object.